Dan Olds, an analyst with Gabriel Consulting Group, says that a good way to approach disaster recovery testing inside an enterprise is to do it one system at a time to minimize the impact on your IT staff and procedures.

"It's not only testing your [disaster recovery] vendors to be sure that it can all be done in an emergency, but it's teaching your people how to do it," Olds says. "It's getting that knowledge so they're not scared to death about it if something happens. You've got to get comfortable with it and it's better to get comfortable when you have help and when it's not time- sensitive and do-or-die, like when the floodwaters are rising outside."

Typically, this kind of detailed testing is the thing that customers don't do, he says, and it's a bad decision to leave it out. "You've got to test the applications. You have to have the guts to do it."

Olds stresses that it is important to keep in mind the difference between redundancy and availability when it comes to your enterprise's data and applications in an emergency. "You want to have all of your data protected all of the time so that no matter what happens, you never lose it, other than the last half hour or so of data."

But at the same time, if disaster strikes, you don't need to access all of that data immediately. You have to have quick and sure availability only to the data that is mission critical for the business as you recover from the emergency, he says.